This disclosure relates generally to radiation systems and methods and in particular to image acquisition devices including contrast and spatial resolution enhanced back-scatter shielding.
Various imaging systems including computed tomography (CT), single photon emission computed tomography (SPECT), positron emission tomography (PET), magnetic resonance imaging (MRI), and ultrasound imaging etc. are known and used in acquisition of images. In each imaging system, some kind of detector is used to detect electromagnetic radiation passing through a body of interest. For instance, an X-ray image acquisition system may employ a solid state detector having a detector array including a large number of detector elements or pixels. The detector elements produce image data signals which can be collected, stored, processed, and displayed as digital images. The images acquired may provide detailed information on the structures inside the body of interest, which may be useful e.g. in treatment planning, monitoring, medical diagnosis, security inspection, and in other applications.
It is known that in a radiotherapy system, an image acquisition device may be used in conjunction with a radiation source that produces high energy radiation such as X-rays at Megavolt (MV) energy levels to acquire images. Conventionally, images acquired using radiation at MV energy levels have relatively low contrast as compared to those acquired using radiation of kilo-volt (keV) energy levels since most of MV radiation passes through the image acquisition device without contribution to image signals. The spatial resolution of the acquired images may also be relatively low due to the scattering effect of high energy radiation.
Accordingly, there is a need for image acquisition devices that can be used in conjunction with various radiation sources producing radiation at various energy levels. There is a need for image acquisition devices that can provide images with enhanced contrast and spatial resolution.